The 5V relay is an automatic switch, which is often used in automatic control circuits, and uses a small current signal to control a large current. The input voltage range of the relay signal is 0 to 5V, and its pin configuration is as follows:
Pin1 (End 1): Used to activate the relay; usually this pin is connected to 5 volts on one end and ground on the other.
Pin2 (End 2): This pin is used to activate the relay.
Pin3 (Common (COM)): This pin is connected to the main terminal of the load to make it active.
Pin4 (Normally Closed (NC)): The second terminal of the load is connected to the NC/NO pin. If this pin is connected to a load, it will be turned on before switching.

Pin5 (Normally Open (NO)): If the second terminal of the load is connected to the NO pin, the load will be turned off before switching.

Features of the 5V relay include the following:
Normal voltage is 5V DC
Normal current is 70mA
AC load current Max is 10A at 250V AC or 125V AC
DC load current Max is 10A at 30V DC or 28V DC
Consists of 5 pins, designed in plastic material
Operation time is 10 milliseconds
The release time is 5msec
The maximum switching capacity is 300 operations per minute